Six prisons to close - fewer inmates at Hull

Some 2,600 offenders are held at the prisons targeted for closure, plus three sites which will be partially shut down.

Prisons at Bullwood Hall, Canterbury, Gloucester, Kingston, Shepton Mallet and Shrewsbury will close, while Chelmsford, Hull and Isle of Wight will see some accommodation reduced.

A feasibility study on what would be Britain’s largest prison in London, the North West or North Wales, holding more than 2,000 prisoners, is also to begin, the Ministry of Justice (MoJ) said.

The programme is part of a drive to build new capacity to replace older prisons and bring down the cost of the prison system. It is expected to save £63 million a year.

Justice Secretary Chris Grayling said: “We have to bring down the cost of our prison system, much of which is old and expensive.

“But I never want the courts to be in a position where they cannot send a criminal to prison because there is no place available.

“So we have to move as fast as we can to replace the older parts of our prison system.”

The plans for the super-prison appear to contrast with the views of Mr Grayling’s predecessor Kenneth Clarke who was an advocate of rehabilitation rather than incarceration.

In addition to the super-prison Mr Grayling unveiled plans for four new mini-prisons known as houseblocks.

It is intended to build these at existing prisons at Parc in South Wales, Peterborough in Cambridgeshire, the Mount in Hertfordshire, and Thameside in London. In total they will be able to hold up to 1,260.

The young offenders institution at HMP Ashfield is to be converted into a full adult prison, the MoJ added, while some 200 contractually crowded places at private prisons will be decommissioned.

The announcements follow the opening of the new G4S-run HMP Oakwood near Wolverhampton last year, which has a normal capacity of 1,600 prisoners.

The average cost at Oakwood is £13,200 per place, the MoJ said, which is less than half the average cost of existing prison places, particularly in older facilities, some of which date back to the 18th century.

Some 83,632 inmates were behind bars as of last Friday, down from the record high of 88,179 after the summer’s riots in 2011. MoJ forecasts show the population could hit 90,900 by 2018.

Plans to build a new super-prison are likely to draw comparisons to Labour’s £2.9 billion proposal for three 2,500-capacity “Titan” jails, which was scrapped in 2009.

Juliet Lyon, director of the Prison Reform Trust, said: “Closing prisons and reducing prison numbers offers major social and economic gains but it would be a gigantic mistake if the Justice Secretary were to revive the discredited idea of titans and pour taxpayers’ money down the prison-building drain, when the coalition Government could invest in crime prevention, healthcare and community solutions to crime.”